Where are the log files?

Hi, How do I clear the logs? Such as internet detection, email, system. Some times it relates to private information and I don't want it in the logs. I can't find a wipe or clear function, nor can I find any files that look like logs. How can I clear my logs?

this file was manually reset (safe mode and copy con "{D7FB805D-8827-4A38-8241-340B5D18D9F7}.log" CTRL-Z Enter) only two days ago. it was 9GB (!!!) before the manual reset and the system was showing the effects.

at the very least there should be a way to request an upper bound on these SQLite-based log files.